BMI

Body Mass Index (BMI)

The BMI Application BMI computes Body Mass Index using a person’s height and weight. Using the calculated value, a person is classified into four broad categories:

• Underweight
• Normal weight
• Overweight
• Obese

BMI Calculations

In metric system, the formula is:

(weight in kg) / (height in meters * height in meters)

In British units, the formula is:

 (703 *  weight in pounds) / (height in inches * height in inches)

A sample calculation for a person with 100 lbs and 5 feet (or 60 inches) is shown below using the R programming language:

bmi <- 703 * 100 / (60 * 60)
bmi

## [1] 19.52778

BMI Ranges

• Below 18.5 Underweight
• 18.5 – 25 Normal weight
• 25 – 30 Overweight
• Above 30 Obese

There are slight variations in the classification ranges in different countries of the world.

The classification for children (defined as people below age 20) is dependent on the age and is done using special tables or graphs.

BMI Use

A person can use the BMI classification to set up appropriate

• physical activities
• food consumption habits

A simple web based application using Shiny to calculate BMI in British Units is available at:

https://rr62.shinyapps.io/bmi3/

Source code is avaiable at:

https://github.com/rr62/musical-invention/